studiot Posted May 9, 2012 Posted May 9, 2012 (edited) Hello, Royston. Thank you for posting your derivations. As I noted you have ably demonstrated that 1) The variables in the classical equations are real observables (Energy, momentum, force etc). 2) The Schrodinger main variable is psi - a variable that requires interpretation. 3) The form of the Schrodinger equation is different from the classical wave equation (you have used the time dependent one the time independent form is the same). In particular the form of the classical equation connects two seconds partials whereas the form of the Schrodinger connects a first partial to a second. For a good discussion of these topics leading to wider horizons I like Elements of Solid State Physics by Rudden and Wilson. This is topical because of course the equations above are for a single isolated (quantum) particle. As soon as we get so some real matter things get more hairy. R & W offer a good transition to this. Finally the last half century has seen the development of several new theories. I think quantum chromodynamics to be currently the most complete theory, but I would be happy to learn of others. Edited May 9, 2012 by studiot
juanrga Posted May 9, 2012 Posted May 9, 2012 (edited) A quantum oscillator is the quantum analogue of a classical oscillator. Have a care with this statement. What do you think the similarity of the classical oscillator equation is to the quantum wave equation? Furthermore are you aware that an oscillator and a wave are different things? What has to see what I said with your questions? I think the comments were clear enough. Again, what has this to see with what I said about the oscillators? You are not the only person allowed to input to this thread (although you have certainly input a great deal and merit thanks for that). Evidently, that is not the question. The question is what has to see what I wrote about oscillators with the above questions that you asked to me? Thanks! Furthermore the original question was why does an electron orbit? None has offered the original poster the obvious simple answer for the same reason the Earth orbits the Sun rather than falling directly into it, althought there is an an attractive force acting here too (gravity). Three or four posters said to the OP that an electron does not orbit. If an electron does not orbit then, evidently, nobody can answer the OP question "what makes an electron orbit?". Nobody will offer to the OP an "obvious simple answer" as yours, because your "Earth orbits the Sun" answer is completely incorrect. This argument has been excessively prolonged because neither side can agree on a definition of either a wave or a particle. This would seem to me a necessary precursor to resolving the argument. You would speak by yourself. I gave the standard definition of particle and dozens of references supporting the well-known fact that an electron is an particle. Thousand of scientist agree on this definition. Personally I am comfortable with the appropriate use of either model - yes they are both (incomplete) models of reality - both serve to more conveniently explain/model/predict one aspect or another of electron behaviour. There is absolutely no known experiment or observation which cannot be explained by the current particle model. The definition of a particle can be something that is wave-like, the only evidence you have provided are traits of particles that are used by quantum wave mechanics. Furthermore the link shows that harmonic oscillator mechanics are used in quantum mechanics and originate from classical wave mechanics. The definition of particle is based in scientific requirements. Particle physicists give a precise definition, which is well-tested in the lab. This is the same definition used by chemists when they claim, officially, that an electron is a particle. There is no reason for which a precise and well-tested definition would be substituted by an imprecise and nonsensical definition as "something that is wave-like". The link that you gave about quantum harmonic oscillators do not support your view, but uses the same quantum mechanics of particles that I am alluding to in my corrections to your posts. Maybe you missed this previous reply: The same link that you give explains how to study the quantum oscillator starting from the "Hamiltonian of the particle", "where m is the particle's mass", and the "first term in the Hamiltonian represents the kinetic energy of the particle", and solving H|Psi> = E|Psi> for the particle (I already wrote this equation before in this thread). And was I wrong to say a a quantum harmonic oscillator was derived from a classical harmonic oscillator to account of the nodal surfaces in atomic orbitals? The quantum harmonic oscillator was not derived to account of the nodal surfaces in atomic orbitals. Not even close! Edited May 9, 2012 by juanrga -1
studiot Posted May 9, 2012 Posted May 9, 2012 Three or four posters said to the OP that an electron does not orbit. If an electron does not orbit then, evidently, nobody cannot answer the OP question "what makes an electron orbit". And nobody will offer to the OP an 'obvious simple answer' as yours, because your answer is completely incorrect. I did not join SF to be insulted.
juanrga Posted May 9, 2012 Posted May 9, 2012 (edited) Hello, Royston. Thank you for posting your derivations. As I noted you have ably demonstrated that 1) The variables in the classical equations are real observables (Energy, momentum, force etc). 2) The Schrodinger main variable is psi - a variable that requires interpretation. psi is not a variable and its physical interpretation is well-known. Born was awarded a Nobel Prize for physics for giving the interpretation of psi. 3) The form of the Schrodinger equation is different from the classical wave equation (you have used the time dependent one the time independent form is the same). In particular the form of the classical equation connects two seconds partials whereas the form of the Schrodinger connects a first partial to a second. Because the Schrödinger equation is not a wave equation. This is more evident when we work with the generalized Dirac formalism of quantum mechanics [math]i\hbar \frac{d |\Psi\rangle}{dt} = \hat{H} |\Psi\rangle[/math] Finally the last half century has seen the development of several new theories. I think quantum chromodynamics to be currently the most complete theory No. Quantum chromodynamics is only the QFT of the strong interactions and involves particles such as quarks and gluons. This theory does not explain the behaviour and interactions of particles such as electrons and photons, for instance. Edited May 9, 2012 by juanrga
questionposter Posted May 9, 2012 Posted May 9, 2012 (edited) The definition of particle is based in scientific requirements. Particle physicists give a precise definition, which is well-tested in the lab. This is the same definition used by chemists when they claim, officially, that an electron is a particle. There is no reason for which a precise and well-tested definition would be substituted by an imprecise and nonsensical definition as "something that is wave-like". There obviously isn't a precise definition of a particle if there's like 10 variations of quantum mechanics that all describe how particles act, and there's even a chemist I know that uses quantum wave mechanics of particles for industrial calculations. The link that you gave about quantum harmonic oscillators do not support your view, but uses the same quantum mechanics of particles that I am alluding to in my corrections to your posts. Maybe you missed this previous reply: How does it NOT support my view? If anything its empirical evidence that quantum mechanics uses quantum wave mechanics to describe particles. The quantum harmonic oscillator was not derived to account of the nodal surfaces in atomic orbitals. Not even close! Ok, AND vector states and the double slit experiment, but scientists think it works well because the nodal surfaces generated by a quantum harmonic oscillator perfectly or nearly perfectly matches where electrons don't seem to show up at all in an atom. Edited May 9, 2012 by questionposter
juanrga Posted May 10, 2012 Posted May 10, 2012 There obviously isn't a precise definition of a particle if there's like 10 variations of quantum mechanics that all describe how particles act There is a precise definition. It was given. The existence of several (philosophical) interpretations of quantum mechanics is not the same than your claim "there's like 10 variations of quantum mechanics". How does it NOT support my view? Ok, AND vector states and the double slit experiment, but scientists think it works well because the nodal surfaces generated by a quantum harmonic oscillator perfectly or nearly perfectly matches where electrons don't seem to show up at all in an atom. I will merely quote an excellent advice that other poster wrote to you: Please stop just grabbing tid bits of information and sticking them into discussions that are not related. It's if you're doing cursory glances at wikipedia, not bothering to understand what the terminology means, and whacking it into discussions. It's very frustrating for people trying to answer you're questions, because you're muddling things up and derailing threads, through people trying to explain to you what the terminology means, and why it's not related. Stick to short, succinct questions, understand the answer, then move on to something else, rather than jumbling stuff up. Sorry if that comes across as patronizing, that's not my intention.
questionposter Posted May 10, 2012 Posted May 10, 2012 (edited) There is a precise definition. It was given. Then state it if it's so precise and it was already stated, because let's just say I don't see it anywhere and that I won't see it if you name a specific post number. The existence of several (philosophical) interpretations of quantum mechanics is not the same than your claim "there's like 10 variations of quantum mechanics". So you think Hamiltonian operators and Dirac mechanics and Schrodinger mechanics and Heisenberg mechanics and Quantum Field Theory are philosophies now? I can name more: There's also Bohmian mechanics, some later Bhor mechanics after even discussed how his model was flawed, DeBroglie (which I guess DeBroglie was in the earlier discovery), Einstein even went into it a little bit even though he didn't like the improbability it had, there's string theory, Calabi-Yau mechanics, etc... And many of these use waves and quantum variations of harmonic oscillators. I will merely quote an excellent advice that other poster wrote to you: Except neither you nor him specified what those "random bits" are. Edited May 10, 2012 by questionposter
juanrga Posted May 10, 2012 Posted May 10, 2012 Then state it if it's so precise and it was already stated, because let's just say I don't see it anywhere and that I won't see it if you name a specific post number. I have given it several times. Several posters noticed it. You can search it by yourself instead asking me again. So you think Hamiltonian operators and Dirac mechanics and Schrodinger mechanics and Heisenberg mechanics and Quantum Field Theory are philosophies now? You would read what I wrote, instead making such ridiculous questions.
questionposter Posted May 10, 2012 Posted May 10, 2012 (edited) I have given it several times. Several posters noticed it. You can search it by yourself instead asking me again. Actually, many people have complained about how you didn't give a precise definition and how you kept saying you already stated it. You would read what I wrote, instead making such ridiculous questions. But my claims were not of philosophical interpretations, they were talking about those mechanics, which you also supported until I pointed out they use wave mechanics. You also weren't very clear either. Did you mean "If the existence..." and "thEn" instead of "thAn"? Edited May 10, 2012 by questionposter
juanrga Posted May 10, 2012 Posted May 10, 2012 Actually, many people have complained about how you didn't give a precise definition and how you kept saying you already stated it. Two complained because the link did not work for them, but next I gave a snapshot from the link. But my claims were not of philosophical interpretations, they were talking about those mechanics, which you also supported until I pointed out they use wave mechanics. You also weren't very clear either. Did you mean "If the existence..." and "thEn" instead of "thAn"? Read what I wrote, it is so simple like that.
questionposter Posted May 10, 2012 Posted May 10, 2012 (edited) Two complained because the link did not work for them, but next I gave a snapshot from the link. The link where you said it contained the official definition of an electron which was that it was something with 1/2 spin, x mass, etc? You know all of that is used in quantum wave mechanics right? Read what I wrote, it is so simple like that. What you wrote is not proper enough English, I don't know what you meant. Edited May 10, 2012 by questionposter
hypervalent_iodine Posted May 10, 2012 Posted May 10, 2012 ! Moderator Note This thread has been closed as staff feel it is too far gone to be brought back to the original topic. It really isn't that difficult to start a new thread should you feel things start to get too off topic. In fact, Royston did exactly that.You can continue to add to the topic there, though be warned, the attitude exhibited in this thread by some is not acceptable and will not be allowed to continue in the other thread. 1
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